Fix Rails::Initializer since #view_paths is never nil

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6127 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

railties/lib/initializer.rb

@@ -273,8 +273,8 @@ def initialize_framework_logging
     # paths have already been set, it is not changed, otherwise it is
     # set to use Configuration#view_path.
     def initialize_framework_views
-      ActionMailer::Base.template_root ||= configuration.view_path    if configuration.frameworks.include?(:action_mailer)
-      ActionController::Base.view_paths ||= [configuration.view_path] if configuration.frameworks.include?(:action_controller)
+      ActionMailer::Base.template_root ||= configuration.view_path  if configuration.frameworks.include?(:action_mailer)
+      ActionController::Base.view_paths = [configuration.view_path] if configuration.frameworks.include?(:action_controller) && ActionController::Base.view_paths.empty?
     end
 
     # If ActionController is not one of the loaded frameworks (Configuration#frameworks)